Inspection lamp



Aug. 10, 1937. w. a. KOERBER INSPECTION LAMP Filed NOV. 21, 1935 INVENTOR III III) ATTORNEY-S Patented Aug. 10, 1937 STATES ATENT OFFEQE INSPECTION LAMP Application November 2 Claims.

This invention relates to electric light extensions and has for its object to provide a device of this kind particularly adaptable for the inspection of beer kegs and the like.

A workman employed in places where there is a damp atmosphere or where the light cable may be watersoaked is often in danger of electrocution from contact with the power line. It is an object of this invention to provide a light extension which will be safe to handle under such conditions.

Another object is to provide a bulb holder comprising an extensible means such that it may be inserted to varying depths and during insertion, withdrawal and non-use it will protect the bulb against breakage from contact with a hard object.

Other objects and advantages will become hereinafter more fully apparent as reference is had to the accompanying drawing wherein my invention is illustrated, by way of example and in which- Figure l is a somewhat schematic illustration of my invention applied to the interior of a keg;

Fig. 2 is a side view of the extensible holder, considerably enlarged, and

Fig. 3 is a longitudinal diametric section through Fig. 2.

More particularly, 1 indicates a beer keg which is often provided with a liner of pitch and when returned to a brewery for re-filling is usually filled with a damp atmosphere. By illustrating a beer keg I do not mean to limit my invention to this use since it may obviously find numerous other uses, more or less similar to the problem of keg inspection.

Inserted into an opening 2 of the keg l is an electric light bulb 3 carried by a stifi tube 4 of metal or other suitable material through which cables 5 are inserted for conducting current from a suitable source of electric power 6. The tube 4 is equipped with a flange or shoulder 21, 1935, Serial No. 50,824

portion 1' against which a coil spring 8 abuts, the other end of this spring resting against an internal shoulder 8 on a surrounding tube Hi. The inside surface of the shoulder 9 and the outside surface of the shoulder l comprise bearing surfaces for relative sliding contact between the tubes 4 and Ill. The inner end of the tube It! is provided with extensions l l of such length that they will bridge the opening 2. The outer end of the tube it extends outwardly beyond the bulb 3 when the holder is in fully retracted position, as illustrated in Fig. 3.

The bulb is set in hard rubber l2, or other suitable insulation, in the tube It, and a suitable cap l3 covers the end of the tube 4.

When pressure is exerted axially on the tube 4 and the extensions I l are held, the tube 4 slides through the tube I thus compressing the spring 8 and fully uncovering the bulb. It may, of course, assume any position between that shown in Figs. 2 and 3 and that shown in Fig. 1 where it is fully extended.

The cable is connected to a transformer M which is provided for the purpose of materially reducing the voltage of the usual city power line below that which will be dangerous to an operator through whose body it may pass.

What I claim is:-

1. In an electric light extension, a bulb holder comprising a protective casing having an internal shoulder, a bulb, the outer end of said casing normally enveloping said bulb, a holder tube in the end of which said bulb is positioned, said tube having a shoulder externally thereon, said tube extending through said casing in slidable engagement therewith, and a spring between said shoulders for urging said tube and said casing into bulb covering position.

2. The combination as set forth in claim 1 together with manual grip means extending outwardly from said casing.

WILLIAM G. KOERBER. 

